In recent years, there has been an increasing demand for performing monitoring or maintenance of facilities including a boiler and thermal power turbine or monitoring of energy consumption remotely at a center far away from a site. Data items of sensors or cameras for video surveillance generated at a terminal of such a monitoring system are ideally all collected to the center side. Along with an increase in the number of sensors or cameras for video surveillance, it has become difficult to collect all of the data items into the center side all the time, due to a limitation on available traffic capacity of a network.
In order to cope with the foregoing circumstances, for example, Patent Literature 1 has disclosed a technology that controls a priority of transfer and display of picture data sent from a camera on the basis of priority information obtained through communication between a mobile node and a stationary node.